[clang] [libc] [llvm] [OpenMP][libc] Remove special handling for OpenMP printf (PR #98940)
Joseph Huber via cfe-commits
cfe-commits at lists.llvm.org
Fri Jul 26 13:56:44 PDT 2024
https://github.com/jhuber6 updated https://github.com/llvm/llvm-project/pull/98940
>From 9195ed11dde78e04c831a5bcb6f9c1cc0e6f0304 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Mon, 15 Jul 2024 12:42:09 -0500
Subject: [PATCH] [OpenMP][libc] Remove special handling for OpenMP printf
Summary:
Currently there are several layers to handle `printf`. Since we now have
varargs and an implementation of `printf` this can be heavily
simplified.
1. The frontend renames `printf` into `omp_vprintf` and gives it an
argument buffer.
Removing 1. triggered some code in the AMDGPU backend menat for HIP /
OpenCL, so I hadded an exception to it.
2. Forward this to CUDA vprintf or ignore it.
We no longer need special handling for it since we have varargs. So now
we just forward this to CUDA vprintf if we have libc, otherwise just
leave `printf` as an external function and expect that `libc` will be
linked in.
---
clang/lib/CodeGen/CGBuiltin.cpp | 2 -
clang/lib/CodeGen/CGGPUBuiltin.cpp | 29 -------
clang/lib/CodeGen/CodeGenFunction.h | 1 -
libc/config/gpu/entrypoints.txt | 1 -
libc/spec/gpu_ext.td | 8 --
libc/src/gpu/CMakeLists.txt | 12 ---
libc/src/gpu/rpc_fprintf.cpp | 75 -------------------
libc/src/gpu/rpc_fprintf.h | 23 ------
.../AMDGPU/AMDGPUPrintfRuntimeBinding.cpp | 3 +-
offload/DeviceRTL/include/LibC.h | 1 -
offload/DeviceRTL/src/LibC.cpp | 44 ++++-------
11 files changed, 16 insertions(+), 183 deletions(-)
delete mode 100644 libc/src/gpu/rpc_fprintf.cpp
delete mode 100644 libc/src/gpu/rpc_fprintf.h
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 0c4d0efb70ea5..f0651c280ff95 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -5986,8 +5986,6 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
getTarget().getTriple().isAMDGCN() ||
(getTarget().getTriple().isSPIRV() &&
getTarget().getTriple().getVendor() == Triple::VendorType::AMD)) {
- if (getLangOpts().OpenMPIsTargetDevice)
- return EmitOpenMPDevicePrintfCallExpr(E);
if (getTarget().getTriple().isNVPTX())
return EmitNVPTXDevicePrintfCallExpr(E);
if ((getTarget().getTriple().isAMDGCN() ||
diff --git a/clang/lib/CodeGen/CGGPUBuiltin.cpp b/clang/lib/CodeGen/CGGPUBuiltin.cpp
index b2340732afeb5..84adf29e8db87 100644
--- a/clang/lib/CodeGen/CGGPUBuiltin.cpp
+++ b/clang/lib/CodeGen/CGGPUBuiltin.cpp
@@ -42,28 +42,6 @@ llvm::Function *GetVprintfDeclaration(llvm::Module &M) {
VprintfFuncType, llvm::GlobalVariable::ExternalLinkage, "vprintf", &M);
}
-llvm::Function *GetOpenMPVprintfDeclaration(CodeGenModule &CGM) {
- const char *Name = "__llvm_omp_vprintf";
- llvm::Module &M = CGM.getModule();
- llvm::Type *ArgTypes[] = {llvm::PointerType::getUnqual(M.getContext()),
- llvm::PointerType::getUnqual(M.getContext()),
- llvm::Type::getInt32Ty(M.getContext())};
- llvm::FunctionType *VprintfFuncType = llvm::FunctionType::get(
- llvm::Type::getInt32Ty(M.getContext()), ArgTypes, false);
-
- if (auto *F = M.getFunction(Name)) {
- if (F->getFunctionType() != VprintfFuncType) {
- CGM.Error(SourceLocation(),
- "Invalid type declaration for __llvm_omp_vprintf");
- return nullptr;
- }
- return F;
- }
-
- return llvm::Function::Create(
- VprintfFuncType, llvm::GlobalVariable::ExternalLinkage, Name, &M);
-}
-
// Transforms a call to printf into a call to the NVPTX vprintf syscall (which
// isn't particularly special; it's invoked just like a regular function).
// vprintf takes two args: A format string, and a pointer to a buffer containing
@@ -213,10 +191,3 @@ RValue CodeGenFunction::EmitAMDGPUDevicePrintfCallExpr(const CallExpr *E) {
Builder.SetInsertPoint(IRB.GetInsertBlock(), IRB.GetInsertPoint());
return RValue::get(Printf);
}
-
-RValue CodeGenFunction::EmitOpenMPDevicePrintfCallExpr(const CallExpr *E) {
- assert(getTarget().getTriple().isNVPTX() ||
- getTarget().getTriple().isAMDGCN());
- return EmitDevicePrintfCallExpr(E, this, GetOpenMPVprintfDeclaration(CGM),
- true);
-}
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index bd62c65d8cce6..89cc819c43bb5 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -4536,7 +4536,6 @@ class CodeGenFunction : public CodeGenTypeCache {
RValue EmitNVPTXDevicePrintfCallExpr(const CallExpr *E);
RValue EmitAMDGPUDevicePrintfCallExpr(const CallExpr *E);
- RValue EmitOpenMPDevicePrintfCallExpr(const CallExpr *E);
RValue EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
const CallExpr *E, ReturnValueSlot ReturnValue);
diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index df7aa9e319624..157f6f8af00a9 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -226,7 +226,6 @@ set(TARGET_LIBC_ENTRYPOINTS
# gpu/rpc.h entrypoints
libc.src.gpu.rpc_host_call
- libc.src.gpu.rpc_fprintf
)
set(TARGET_LIBM_ENTRYPOINTS
diff --git a/libc/spec/gpu_ext.td b/libc/spec/gpu_ext.td
index 5400e0afa7564..dce81ff778620 100644
--- a/libc/spec/gpu_ext.td
+++ b/libc/spec/gpu_ext.td
@@ -10,14 +10,6 @@ def GPUExtensions : StandardSpec<"GPUExtensions"> {
RetValSpec<VoidType>,
[ArgSpec<VoidPtr>, ArgSpec<VoidPtr>, ArgSpec<SizeTType>]
>,
- FunctionSpec<
- "rpc_fprintf",
- RetValSpec<IntType>,
- [ArgSpec<FILERestrictedPtr>,
- ArgSpec<ConstCharRestrictedPtr>,
- ArgSpec<VoidPtr>,
- ArgSpec<SizeTType>]
- >,
]
>;
let Headers = [
diff --git a/libc/src/gpu/CMakeLists.txt b/libc/src/gpu/CMakeLists.txt
index 4508abea7a888..e20228516b511 100644
--- a/libc/src/gpu/CMakeLists.txt
+++ b/libc/src/gpu/CMakeLists.txt
@@ -8,15 +8,3 @@ add_entrypoint_object(
libc.src.__support.RPC.rpc_client
libc.src.__support.GPU.utils
)
-
-add_entrypoint_object(
- rpc_fprintf
- SRCS
- rpc_fprintf.cpp
- HDRS
- rpc_fprintf.h
- DEPENDS
- libc.src.stdio.gpu.gpu_file
- libc.src.__support.RPC.rpc_client
- libc.src.__support.GPU.utils
-)
diff --git a/libc/src/gpu/rpc_fprintf.cpp b/libc/src/gpu/rpc_fprintf.cpp
deleted file mode 100644
index 70056daa25e2e..0000000000000
--- a/libc/src/gpu/rpc_fprintf.cpp
+++ /dev/null
@@ -1,75 +0,0 @@
-//===-- GPU implementation of fprintf -------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "rpc_fprintf.h"
-
-#include "src/__support/CPP/string_view.h"
-#include "src/__support/GPU/utils.h"
-#include "src/__support/RPC/rpc_client.h"
-#include "src/__support/common.h"
-#include "src/__support/macros/config.h"
-#include "src/stdio/gpu/file.h"
-
-namespace LIBC_NAMESPACE_DECL {
-
-template <uint16_t opcode>
-int fprintf_impl(::FILE *__restrict file, const char *__restrict format,
- size_t format_size, void *args, size_t args_size) {
- uint64_t mask = gpu::get_lane_mask();
- rpc::Client::Port port = rpc::client.open<opcode>();
-
- if constexpr (opcode == RPC_PRINTF_TO_STREAM) {
- port.send([&](rpc::Buffer *buffer) {
- buffer->data[0] = reinterpret_cast<uintptr_t>(file);
- });
- }
-
- port.send_n(format, format_size);
- port.recv([&](rpc::Buffer *buffer) {
- args_size = static_cast<size_t>(buffer->data[0]);
- });
- port.send_n(args, args_size);
-
- uint32_t ret = 0;
- for (;;) {
- const char *str = nullptr;
- port.recv([&](rpc::Buffer *buffer) {
- ret = static_cast<uint32_t>(buffer->data[0]);
- str = reinterpret_cast<const char *>(buffer->data[1]);
- });
- // If any lanes have a string argument it needs to be copied back.
- if (!gpu::ballot(mask, str))
- break;
-
- uint64_t size = str ? internal::string_length(str) + 1 : 0;
- port.send_n(str, size);
- }
-
- port.close();
- return ret;
-}
-
-// TODO: Delete this and port OpenMP to use `printf`.
-// place of varargs. Once varargs support is added we will use that to
-// implement the real version.
-LLVM_LIBC_FUNCTION(int, rpc_fprintf,
- (::FILE *__restrict stream, const char *__restrict format,
- void *args, size_t size)) {
- cpp::string_view str(format);
- if (stream == stdout)
- return fprintf_impl<RPC_PRINTF_TO_STDOUT>(stream, format, str.size() + 1,
- args, size);
- else if (stream == stderr)
- return fprintf_impl<RPC_PRINTF_TO_STDERR>(stream, format, str.size() + 1,
- args, size);
- else
- return fprintf_impl<RPC_PRINTF_TO_STREAM>(stream, format, str.size() + 1,
- args, size);
-}
-
-} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/gpu/rpc_fprintf.h b/libc/src/gpu/rpc_fprintf.h
deleted file mode 100644
index 7658b214c07c2..0000000000000
--- a/libc/src/gpu/rpc_fprintf.h
+++ /dev/null
@@ -1,23 +0,0 @@
-//===-- Implementation header for RPC functions -----------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIBC_SRC_GPU_RPC_HOST_CALL_H
-#define LLVM_LIBC_SRC_GPU_RPC_HOST_CALL_H
-
-#include "hdr/types/FILE.h"
-#include "src/__support/macros/config.h"
-#include <stddef.h>
-
-namespace LIBC_NAMESPACE_DECL {
-
-int rpc_fprintf(::FILE *__restrict stream, const char *__restrict format,
- void *argc, size_t size);
-
-} // namespace LIBC_NAMESPACE_DECL
-
-#endif // LLVM_LIBC_SRC_GPU_RPC_HOST_CALL_H
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp b/llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp
index 42a6bac4fa6f2..02b0d436451a3 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp
@@ -437,7 +437,8 @@ bool AMDGPUPrintfRuntimeBindingImpl::run(Module &M) {
return false;
auto PrintfFunction = M.getFunction("printf");
- if (!PrintfFunction || !PrintfFunction->isDeclaration())
+ if (!PrintfFunction || !PrintfFunction->isDeclaration() ||
+ M.getModuleFlag("openmp"))
return false;
for (auto &U : PrintfFunction->uses()) {
diff --git a/offload/DeviceRTL/include/LibC.h b/offload/DeviceRTL/include/LibC.h
index dde86af783af9..59a795cc62e0e 100644
--- a/offload/DeviceRTL/include/LibC.h
+++ b/offload/DeviceRTL/include/LibC.h
@@ -18,7 +18,6 @@ extern "C" {
int memcmp(const void *lhs, const void *rhs, size_t count);
void memset(void *dst, int C, size_t count);
-
int printf(const char *format, ...);
}
diff --git a/offload/DeviceRTL/src/LibC.cpp b/offload/DeviceRTL/src/LibC.cpp
index 4bca5d29643fe..291ceb023a69c 100644
--- a/offload/DeviceRTL/src/LibC.cpp
+++ b/offload/DeviceRTL/src/LibC.cpp
@@ -11,44 +11,33 @@
#pragma omp begin declare target device_type(nohost)
namespace impl {
-int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t);
+int32_t omp_vprintf(const char *Format, __builtin_va_list vlist);
}
+#ifndef OMPTARGET_HAS_LIBC
+namespace impl {
#pragma omp begin declare variant match( \
device = {arch(nvptx, nvptx64)}, \
implementation = {extension(match_any)})
-extern "C" int32_t vprintf(const char *, void *);
-namespace impl {
-int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t) {
- return vprintf(Format, Arguments);
+extern "C" int vprintf(const char *format, ...);
+int omp_vprintf(const char *Format, __builtin_va_list vlist) {
+ return vprintf(Format, vlist);
}
-} // namespace impl
#pragma omp end declare variant
#pragma omp begin declare variant match(device = {arch(amdgcn)})
-
-#ifdef OMPTARGET_HAS_LIBC
-// TODO: Remove this handling once we have varargs support.
-extern "C" struct FILE *stdout;
-extern "C" int32_t rpc_fprintf(FILE *, const char *, void *, uint64_t);
-
-namespace impl {
-int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t Size) {
- return rpc_fprintf(stdout, Format, Arguments, Size);
-}
+int omp_vprintf(const char *Format, __builtin_va_list) { return -1; }
+#pragma omp end declare variant
} // namespace impl
-#else
-// We do not have a vprintf implementation for AMD GPU so we use a stub.
-namespace impl {
-int32_t omp_vprintf(const char *Format, void *Arguments, uint32_t) {
- return -1;
+
+extern "C" int printf(const char *Format, ...) {
+ __builtin_va_list vlist;
+ __builtin_va_start(vlist, Format);
+ return impl::omp_vprintf(Format, vlist);
}
-} // namespace impl
-#endif
-#pragma omp end declare variant
+#endif // OMPTARGET_HAS_LIBC
extern "C" {
-
[[gnu::weak]] int memcmp(const void *lhs, const void *rhs, size_t count) {
auto *L = reinterpret_cast<const unsigned char *>(lhs);
auto *R = reinterpret_cast<const unsigned char *>(rhs);
@@ -65,11 +54,6 @@ extern "C" {
for (size_t I = 0; I < count; ++I)
dstc[I] = C;
}
-
-/// printf() calls are rewritten by CGGPUBuiltin to __llvm_omp_vprintf
-int32_t __llvm_omp_vprintf(const char *Format, void *Arguments, uint32_t Size) {
- return impl::omp_vprintf(Format, Arguments, Size);
-}
}
#pragma omp end declare target
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